What is a Public Key?

A public key is a cryptographic code mathematically derived from a private key that serves as the foundation for creating blockchain addresses, enabling users to receive assets and verify signatures without exposing the private key that controls those assets.

Through asymmetric cryptography, public keys work in tandem with private keys to create a secure system where funds can be sent to a public address (derived from the public key), but only the holder of the corresponding private key can authorize transactions spending those funds.

Public keys can be freely shared without security concerns, functioning somewhat like an account number in traditional banking, though in most blockchain systems users typically share derived addresses rather than the actual public key for additional security benefits.

The cryptographic relationship between private and public keys enables critical blockchain functions including digital signatures, where messages or transactions signed with a private key can be verified using the corresponding public key, proving authenticity without revealing the private key.

This public-private key architecture forms the foundation of blockchain security and self-custody, creating a system where users can participate in the network and receive assets without relying on centralized account providers, while maintaining complete control over their funds through proper management of their private keys.